Concertina razor barbed wire on the top of wire mesh fence 

1. Concertina razor barbed wire is a mesh of metal strips with sharp edges whose purpose is to prevent passage by humans.
2. The multiple blades of a concertina razor barbed wire fence are designed to inflict serious cuts on anyone attempting to climb through and therefore have a strong psychological
3. Deterrent effect.
4. In many high-security applications, concertina razor barbed wire supplanted barbed wire, which could be circumvented relatively quickly by humans with tools, while penetrating razor wire barriers without tools is very slow and difficult, giving security forces more time to respond.
5. Concertina razor barbed wire contains a core hardened steel strip that is often under tension, so if cut, it strikes the cutter.

1. Like barbed wire, concertina razor barbed wire is available as either straight wire or spiral concertina wire.
2. Unlike barbed wire, which usually is available only as plain steel or galvanized, barbed tape is also manufactured in stainless steel, to prevent the points from rusting to bluntness.
3. Typically the core wire is galvanized and the tape is stainless, although fully stainless barbed tape is used for expensive permanent installations or under water.